

A121997


Count up to n, n times.


8



1, 1, 2, 1, 2, 1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7
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OFFSET

1,3


COMMENTS

The nth block consists of n subblocks, each of which counts from 1 to n.
This a fractal sequence: removing the first instance of each value leaves the original sequence.
The first comment implies that this gives the column index of the nth element of a sequence whose terms are coefficients, read by rows, of a sequence of matrices of size 1 X 1, 2 X 2, 3 X 3, etc.; cf. example. The row index is given by A238013(n), and the size of the matrix by A074279(n).  M. F. Hasler, Feb 16 2014


LINKS

Table of n, a(n) for n=1..105.


EXAMPLE

1;
1,2;
1,2;
1,2,3;
1,2,3;
1,2,3;
...
The blocks of n subblocks of n terms (n=1,2,3,...) can be cast into a square matrices of order n; then the terms are equal to the index of the column they fall into.


PROG

(PARI) A121997(N=9)=concat(vector(N, i, concat(vector(i, j, vector(i, k, k))))) \\ Note: this creates a vector; use A121997()[n] to get the nth term.  M. F. Hasler, Feb 16 2014


CROSSREFS

Cf. A081489 (locations of new values), A075349 (locations of 1's).
Cf. A000290 (row lengths), A002411 (row sums), A036740 (row products).
Cf. A002024 and references there, esp. in PROG section.
Cf. A238013.
Sequence in context: A248141 A220694 A136314 * A023128 A237260 A249727
Adjacent sequences: A121994 A121995 A121996 * A121998 A121999 A122000


KEYWORD

easy,nonn,tabf


AUTHOR

Franklin T. AdamsWatters, Sep 11 2006


STATUS

approved



